Rotary pump or compressor



.141114,1941.V 4 L ATHQMSQN 2,228,933

'ROTARY PUMP O-R COMPRESSOR iled oct. 4, 1939 4 ,sheets-sheet 1 Jan. 14, 1941. L, A. THoMsoN 2,228,933

ROTARY PUMP OR COMPRESSOR Filed Oct. 4, 1939 4 Sheets-Sheet 2 S11/vendio@ N 14, 1941- L A. THoMsoN ROTARY PUMP on OMPREssoR 4 Sheets-Sheet 3 Filed Oct. 4. 1939 .Mrrumwhvim e NH Mmmm., 14, 1941. L, A "mmmgmw www PUMP on commmsso 4 Shams-Sheet 4 Film1 06%,. 4. 19359 Ril gli

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ROTARY PUMP OR COMPRESSOR Leroy A. Thomson, La Crosse, Wis., assigner to Bump Pump Company, La Crosse, Wis.

Application October 4, 1939, Serial No. 297,928

3 Claims.

This invention relates toy rotary pumps or compressors and more particularly to a compressor or pump which is so constructed that oil or the like will not enter the pumping chamber so as to mix with any fluid passing therethrough, and is an improvement over the structure disclosed by Patent Number 2,161,729, issued to me under date of June, 1939.

An object of this invention is to provide a compressor which is so constructed that it may he operated either with or without `a sealing, cooling and lubricating fluid and which is also con structcd that relatively close tolerances may be `provided between the rotary elements so that the pump may be operated at the desired speed without undue heating or wear thereof.

Another object oi' this invention is to provide a pump ci this character wherein water or other liquid may he used as a sealing, cooling and 1ubricating element, the liquid being mixed with air or gases which are passing through the pump.

A further object. of this invention is to provide in pump of this character a pair of housings which may be secured to a stationary base, one of the housings enclosing the rotary pumping elements and the other housing enclosing gears or the like which are secured to shafts on which the pumping elements are also secured so that the gears may be provided with the desired lubricant which will not come into contact with the rotary elements in the pumping compartments.

A. still further object of this invention is to provide in a pump of this kind a pair of outlet passages, one for each rotor and spring-pressed check valves ior such outlet passages so as to prevent the back pressure from ailecting the operation of the pump.

A further object of this invention is to provide in a pump of this kind a pair of outlet passages, one for each rotor and check valves for such outlet passages so as to prevent any back pressure from affecting the operation of the pump. This pair of outlet passages may have a single cornrnon outlet check valve, but I prefer to show separate valves on account of better efhcicncy. The valve or valves may be of any shape or design desired, such as spring loaded or otherwise, ball, poppet, reed shaped, or otherwise. The valve section may also be made removable for ease of cleaning and repairing.

A further object of this invention is to provide in a pump of this kind, a pair of separate intake passages and a pair of separate discharge passages, with or without check valves for same, so as to allow pumping of two different fluids, with or without the addition o sealing, cooling or lubricating liquids, so that the fluids may be discharged substantially separate from each other.

A further object of this invention is to provide, in a pump of this kind, a pair of separate intake passages, and a pair of separate discharge pasn sages, with or without check valves for same, and with or without the addition of sealing, cooling and lubricating liquids, so that two different iluids may be mixed within the pump and discharged together in substantially equal volumes.

A further object of this invention is to provide a pump of this kind wherein the rotors may be taken off from the operating shafts thereof without the necessity of disassembling the entire pump structure.

To the above objects and others which may hereinafter appear, the invention consists ol' the novel construction, combination and arrangement of parts as will be more specifically referred to and illustrated in the accompanying drawings wherein is shown embodiments of the invention,` i

but it is to be understood that changes, varia tions and modifications may be resorted to which fall Within the scope of the invention as claimed. In the drawings: Figure l is a detail'top plan partly in horizontal section of a pump or compressor constructed according to an embodiment of this invention,

Figure 2 is a detail side elevation partly broken away and in vertical section of the pump,

Figure 3 is a sectional view taken on the line 3-3 of Figure 2,

Figure 4 isa sectional view taken on the line 4-4 of Figure 3, l

Figure 5 is a fragmentary sectional view taken on the line 5-5of Figure 4,

Figure 6 is an enlarged fragmentary sectional view taken on the line 6*-6 of Figure 5,

Figure 7 is a sectional view taken on thelline 'iw-fl of Figure 3,

Figure 8 is a perspective view of one of the rotors from one end of the rotor,

Figure 9 is a perspective view of a rotor looking in the direction opposite from Figure 8,

Figure 10 is a fragmentary sectional View similar to `Figure 3 showing an improved sealing means for the shafts,

Figure 11 is a view similar to Figure 4, but showing a modified form of pump structure, and

Figure l2 is an enlarged fragmentary sectional View taken on the line i2-I2 of Figure 11.

Referring to the drawings, the numeral IU de signates a base structure on which are mounted a pump housing Il and a gear housing i2. he

pump housing I I comprises a casing I4 which is fixed to the base IIJ and which is provided on the inside thereof with a` pair of annular or ringshaped compartments I5 and I6. These compartments I5 and I6 constitute pumping chambers or compartments, and an inlet passage I3 is provided in the casing I4 which at its inner end communicates with the two compartments I5 and I6.

The casing I4 is provided with a pair of outlet K or discharge passages I1 and I8 which communicate with the compartments or chambers I5 and I6 respectively. These discharge passages or orifices I1 and I8 communicate with a connecting passage I9 which discharges into a common outlet or discharge opening 20 provided in the present instance in the base I0; 'A drive shaft 2| passes through the casing I4 and may or may not be journaled in the casing. The casing I4 is provided with a gland member 22 which engages about the shaft 2| and is tightly secured to the casing I4 by means of bolts 23 or the like. Soft packing 24 engages in a stuiing box 25 provided in the casing I4 so as to tightly seal the shaft 2| at one end of the casing I4. A second or driven shaft 26 passes through the casing I4 in like mann'er in parallel relation to the drive shaft 2| which extends through a stufiing box 21. A gland member 28 similar to the gland 22 engages in the stufiing box 21 and a sealing member 29 is positioned in the stufiing box 21. The gland 28 is held about the shaft 26 and to the casing by bolts 36 or the like. A rotor 3| comprising one of a pair of rotary pumping members is rotatably disposed in the pumping chamber I5. The rotor 3| comprises a hub 32 and a crescent-shaped or segmental off-set part 33 which is disposed within the chamber I5. The hub 32 as shown in Figure 3 is disposed exteriorly of the chamber I5 and is secured to the shaft 2| by key members 3'4. The key members 34 in the present instance are segmental shaped and are held against movement relative to the hub member 32 by means of a set screw 35. The opposite ends of the crescentshaped or segmental rotor 32 are provided with arcuate or concave portions 36, the purpose for which will hereinafter be described.

A second rotor 31 is disposed in the pumping chamber or compartment I6 and comprises a crescent-shaped rotor 38 secured in olf-set relation to a hub 39 which is xed to the driven shaft 26 by means of key members 48. If desired, the rotors 3| and 31 may be splined onto the shafts 2| and 26 respectively. The key members 40 are held against movement relative to the hub members 39 by means of set screws 4| which may be omitted, if desired. The crescent-shaped rotor element 38 is constructed similar t'o the rotor 3| being provided with concave opposite end portions 42. In this manner, the rotation of the two rotors 3| and 31 may be extended in opposite directions and the concave end portions thereof may interengage as shown in Figure 4. The rotors 3| and 31 are adapted, during a portion of the rotation thereof, to cover up the discharge orifices I1 and I8, the covering of these orifices being done alternately so that the fluid in one of the chambers will be forced out of its discharge orifice while the other discharge port is covered by the other rotor.

A cap or closure plate 43 engages against the casing I4 and encloses the hub portions 32 and 39 of the rotors 3| and 31 respectively. The cap 43 is secured in face abutting relation to the adcasing I4 by means of bolts 45 jacent face of the Vof the opening I3 or clamps or the like and may be doweled, if desired. The cap 43 is provided with a pair of bushings 46 and 41 which engage about the shafts 2| and 26 respectively, and sealing glands 48 and 49 engage the stuffing boxes 46 and 41 respective; ly, so as to thoroughly seal the shafts 2| and 26 with respect to the cap 43. These gland members 48 and 49 are similar 'to the gland members 22 and 28 being detachably secured to the cap 43 by means of bolts 23 and 30 respectively.

A plate or end wall 50 is secured to the cap 43 by means of a pair of arms 5I and this plate or wall 50 is provided with a pair ofsockets or recesses 52, -53 in which thrust bearing members, generally indicated as 54 and 55 respectively, are mounted. The drive shaft 2| is provided with a reduced end portion 56 engaging within the inner race 51 of the bearing 54 and this reduced end is also provided with a threaded portion 58 on which a nut 59 is threaded so as to tightly secure the inner race 51 on the reduced end 56 of the drive shaft 2|. In this manner the adjacent end of the drive shaft 2| is rotatably supported by a bearing which includes a thrust bearing in the plate 50. While anti-friction bearings are shown, plain, ball or roller or other types may be used, either singly or in combination. These bearings may be secured to the shaft and to the end wall by various means other than as shown, as by threads, shoulders, tapers or snap rings. The above bearing comments apply both to the driven shaft 26 and drive shaft 2 The driven shaft 26 is provided with a reduced end portion 6I) and the inner race 6I of the bearing member 55 engages about this reduced portion 60 and is tightly held thereon by means of a nut 62 which is threaded onto a threaded end portion 63 of the shaft 26. The bearings 54 and 55 are of the thrust type which in addition also rotatably support the shafts 2| and 26 in the cap 43. A cap 64 encloses the nut 59 being detachably secured to the plate 50 by means of bolts or screws 65 or the like. A second cap 66 encloses about the nut 62 being secured to the plate 50 by means of bolts or screws 61 or the like. In this manner, when it is desired to remove the cap 43, the end caps 64 and 66 are first removed by taking out the screws 65 and 66. The holding nuts 59 and 62 are then removed from the threaded ends of the shafts 2| and 26 respectively. The bolts 45 may then be removed and the cap 43 moved axially of the casing I4.

The inlet pipe 68 is threaded into a boss 69 carried by the casing I4 and this inlet pipe 68 is preferably provided with an interior diameter relatively larger than the diameter of the inlet opening I3. A pipe 10 is disposed concentrically and the pipe 68 being secured to a laterally extending pipe 1| by means of a coupling or elbow 12. The pipe 1I is provided for the purpose of admitting a uld such as water or the like equally into the compartments I5 and I6 which fluid may act as a sealing means to thoroughly seal the rotors.3| and 31 in the compartments I5 and I6 respectively.

It will also be understood that any desired liquid may be provided for a. sealing liquid so that the pump may be used for pumping. either a gas, air or the like or may be used for mixing gas or air with a fluid which is forced out of thedischarge opening 20. This liquid may be either Water, beer or other liquid which would not adversely contaminate the fluid being pumped.

A gear casing 13 is secured to the base I 0 in spaced relation to the casing I4 and comprises a itin stationary housing 14 which is fixed to the base I and may be connected to the casing I4 by a connecting bar or brace 15. The casing 14 is provided on the inside thereof with a pair of bushings 16 and 11 which engage about the shafts 2| and 26 respectively. 'I'he bearing sleeves 18, 19 are provided in the bushings 16 and 11 respectively and are held in place by a press t or otherwise. Oil seals 80 and 8| are provided about shaft 2| and oil seals 8| and 92 are provided'about shaft 26 to prevent leakage of lubrication oil from the gear casing l2 along the shafts 2| and 26.

A driving gear 82 is iixedly secured to the drivev shaft 2| by means of a key 83 or the like and a driven gear 84 is iixedly secured to the driven shaft 26 by means of a key 86 or the like. The gears 82 and 84 mesh with each other so that the driven shaft 26 will rotate in a direction opposite from the drive shaft 2|. A closure plate 86 is secured to the outer open end of the casing 14 by means of bolts 81 or the like. The closure member 86 is constructed in substantially a cup-shaped form being provided with an exterior flange 8B through which the bolts 81 engage. The closure member 86 is also provided with bearing sleeves 89 and 90 engagingabout the drive shaft 20 and the driven shaft 26 respectively. These bearing sleeves are held in the closure member 26 by means of a press nt or otherwise by nuts 9| and 92 respectively.

The casing I4 is provided with a valve seat 93 in the discharge port |1 and a valve member 94 engages on this seat. The valve member 94 is provided with a valve stem 95 which is slidable in a sleeve 96 carried by a nut 91 threaded into -the casing I4 from the exterior thereof. A spring 98 engages at one end against the valve head 94 and at the other end engages against the nut 91 being disposed partly about the sleeve 16 which is integral with the nut 91.

The casing I4 is also provided with a valve seat 99 in the passage or port I8 and a valve |00 engages on this seat 99. The valve |00 is provided wth a stem |0| which is slidable in a sleeve |02 carried by a nut |03 threaded into the casing i4 from the exterior thereof. A spring |04 engages at one end against the valve member |00 and at the other end engages against the nut |03 and is partly disposed about the sleeve |02. Normally the valve members 94 and |00 are in closed position under the tension of the springs 95 and |04 respectively, and are opened by pressure of the iiuid from the chambers I5 and I6. When the pressure in the discharge passage is greater than the pressure in the chambers I5 and I6, the `valves 94 and |00 will be held in closed position so that therey will not be any reverse flow of th-e iiuid through the pump structure. The valve design shown is only one of many which may be used. It should be understood that my invention is not limited to any one valve design, but that any desirable variety may be used, depending upon the requirements to be satisfied.

In `Figure 10 there is disclosed an improved means for providing a liquid sealing for the drive shafts 2 |a and 26f. The casing" |4a is formed with a pair of annular compartments I6a and I6 similar to the structure shown in Figures 1 to 4 inclusive and a. pairof rotors 3|* and 38* are secured to the shafts 2 IIl and 26L respectively and a bushing is disposed about the shaft 2 le. The second bushing 21 is disposed about the shait 26a and gland members 22n and 28 are threaded into the bushings 25* and 21. A packing 24 is disposed in the bushing 25* and is adapted to be compressed about the shalt 2| by the 4tightening of the gland member 22e. A packing 2|!a is disposed in the bushing 21a and is adapted to be tightened by the gland member 20a.

The housing |148L is provided with an annular groove or chamber |05 inwardly of the packing member 24a and the housing I4a is also provided with a second annular chamber |06 about the shaft 26 and inwardly ofV the packing 20, A pipe |01 provided `with a pair of branches |08 and |09 is adapted to be connected at one end to a source of liquid supply such as oil or the like and the branch |08 communicates with the pipe |01 and with the annular chamber |05. The branch |08 communicates with the pipe |01 and with the annular chamber |06.

The cap 43a is secured as by bolts 45a to the housing IllA and includes a pair of bushings i6a and 41Ei about the shafts 2|a and 26. Gland members 48EL and I9a are threaded into the bushings IISa and 41a respectively. A pair of packing members ||0 and are disposed in the bushing 46a and a spacer member or washer II2 is interposed between the two packing members I0 and III. This spacer member I|2 is preferably apertured to permit a sealing liquid discharged in the space betweenthe two packing members |0 and to contact with the shaft 2|a. A pair of packing members ||3 and ||4 are disposed in the bushing 41 and a spacer member ||5 is interposed between the two packing members ||3 and H6. This spacer member II5 is of an apertured type to permit a sealing liquid engaging in the space between the packing members |I3 and |I4 to contact with the shaft 26a. A pipe |I6 is adapted to be connected at one end to a source of liquid supply andthe opposite end of the pipe II6 is connected to a pair of branch pipes ||1 and ||8 which are connected to the bushings 46a and 41v respectively. These branches ||1 and ||8 are adapted to discharge a sealing liquid between the respective pairs of packing members.

In other respects the structure shown in.. Figure 10 is similar to the structure shown in `Figures 1 to 4 inclusive.

In Figures l1 and 12 there is disclosed a modified form of this pump structure wherein the housing I4b is disclosed similar to the housing I4, being provided with a pair of annular chambers Iiib and I6b. A rotor 3|b is disposed in the chamber I5b and is secured to a drive shaft 2lb. A rotor 31b is disposed in the chamber I6'J and is secured to a driven shaft 26h.

The housing I 4b is provided with an intake port II9 communicating with the chamber I5D and an intake pipe 68h is secured to a boss 69h. A second intake port |20 is formed in the housing I4b which communicates with the chamber I6b and an intake pipe 68c is mounted in a bess or bushing 69's. The pipe 68c communicates with the port |20. A dividing wall or partition |2I divides the two ports II9 and |20.

The housing I4b is provided with an outlet port I1b which communicates with a discharge port 2|)b mounted in the base |0. The housing |4b is also provided with an outlet port I8h communicating with the chamber ||h and an outlet or discharge port 20c communicates with the outlet |811. A check valve 94b is adapted to engage a seat 93b and is constantly held against the seat 93b by means of a spring 98h. The valve member 94b is provided with a stem 95b and this stem 95b is slidable in a guide member 96b carried by a spring tensioning plug Blb which is threaded into the housing |41.

A second check valve |b is adapted to be held on a seat 99b by means of a spring |04". The valve |001 is provided with a stem |0|b which is slidable in a guide member |025. The guide member |02b is carried by a threaded plug |03b.

With a construction as shown in Figures 10 and 1l two different fluids may be pumped and kept substantially separate one from another and discharged separately from the discharge ports 2Gb and 20C.

In the use and operation of this pump or com-v pressor the pipe 60 is adapted to be connected to a source of fluid supply or if desired may be opened to the atmosphere. The pipe is connected -to a source of liquid supply such as water, beer or; other liquid which may be used as a sealing means in the pumping chambers I and I6. The drive shaft 2| is connected to the source of power supply and rotation of the drive shaft 2| will effect reverse rotation of the driven shaft 26. The rotation of the rotors 3| and 3`| will produce apartial vacuum in the pumping chambers |5 and i6 so as to draw in the uid through" thesupply pipe 68 and through the inlet opening I3. As shown in Figure 4, the casing |4 has a hub portion 44 which is cut out as at 44a on.

the side thereof confronting the opposite hub portion in the chamber I6 which is designated 44h. In thismanner the rotor'3l is able to swing past the hub 44 and the rotor 3| is able to swing past the hub portion 44b which is cut out as at 44. The fluid drawn into the casing |4 by rotation of the ,rotor 3| will be carried around in the pumping chamber |5 and as the rotor 31 passes the outlet opening I8 further rotation of the rotor 3| will cause the fluid to impinge against the confronting arcuate side of the rotor 3'! and then be forced out through the discharge passage or port Il. The valve 94 will at this time be forced into an open position so that the liquid or fluid will pass through the connecting passage |9 and into the common outlet 20. IThe rotation of the rotor 31 will effect similar discharge of the liquid or fluid through the discharge port I8 and cause the valve |00 to be forced to an open position. Due to the fact that the gear structure for the rotors is mounted in a separate housing from the pumping member the-lubricant used in the gear housing will not seep into the pumping chambers and the rotors may be given closer tolerances in the annular pumping chambers I5 and I6 than is ordinarily the case. This closer tolerance between the rotors and the walls of the pumping chambers will make it possible `to operate the pump Without the use of a sealing or lubricating fluid, but if desired a sealing fluid in` the form of water or the like may be discharged into the casing |4 through the fluid pipe 10, 1| which is disposed concentrically in the inlet opening I3.

Where it is desired to take the pump proper apart, this procedure may be accomplished by taking the cap members 64 and 68 off of the bearing plate 50 and loosening the nuts 59 and 62 from the shafts 2| and 26. The bolts 45 may then bewithdrawn or removed thus permitting the removal of the cap or closure plate 43. The rotors 3| and 31 may then be removed from the shafts 2| and 26 respectively by loosening the set screws 35 and 4| which will permit the hubs 32 and 39 to be pulled olf of the shafts 2| and 26 respectively. This procedure makes it unnecessary to open the gear housing 13 so that none of the lubricant in this housing will flow onto the rotors or any of the parts associated therewith. 'I'he glands or stuffing boxes 22, 28, 48, 49 seal the shafts 2| and' 26 in the pumping member so that when the device is in assembled condition the lubricant in the form of oil or grease from the gear housing 13 will not enter the pumping chambers. i l

Theanti-friction members 54 and 55 carried bythe bearing plate 50 `not only rotatably support the shafts 2| and 26 respectively in the cap 43, but also providethrust bearings which will hold the shafts 2| and 26 against endwise movement. The thrust bearings 54 and 55 are readily'removed from the reduced ends 56 and 60 respectively of the shafts 2| and 2,6 by loosening y of the nuts 59 and 62.

A pump constructed according to this invention is capable of operating at' a relatively high speed so as to produce the desired suction force and may operate either with or without a sealing means which sealing means may also perform the added function of cooling the pumping chambers and the. parts associated therewith as well as absorbing the heat of `c0mpression of the gases being handled. In this manner it is not necessary to provide a jacketed casing structure about the pump chambers in order to adequately cool the structure.

The gears 82 and 04 may be readily removed from the gear housing 13 by removal of the cap 86 thus permitting the longitudinal movement of the gears 82 and 84 which as shown in Figure 3 are held against endwise movement by means of confronting bushings 16 and 'll and the associated bushings carried by the cap member 86.

What I claim is:

l. In a fluid pump, a housing structure formed with a pair of rotor chambers, a pair of oppositely revoluble simultaneously operable parallel rotor operating shafts journalled in said structure, a pair of oppositey disposed rotors of like form each operating in a rotor chamber and formed of a hub fixed to one of said shafts and a crescentshaped part carried by and offset with respect to the hub, an independent uid inlet opening into the upper portion of each chamber and an independent fluid outlet of bore-like form for each chamber, said rotors being so related to said pair of inlet openings whereby one of said inlet openings is uncovered by the crescent-shaped part of one rotor at a time when the other inlet opening is covered bythe crescent-shaped part of the other rotor, each of said outlets having an upper horizontal part leadingrearwardly from and opening at its forward end into the inner side of the lower portion of a chamber, a depending vertically disposed part'opening at its upper end into the horizontal part intermediate the ends of the'latter and a forwardly extending lower horizontal part opening at its'forward end at the front of the housing'and at its rear end into the lower end of said vertical part, the wall of each of said upper horizontal parts being formed intermediate its ends with a check valve seat, a spring cont-rolled check valve within each upper horizontal part for correlation with the valve seat in such part, and adjustable means within each upper horizontal part threadedly engaging with the wall of such part for adjusting the tension of the check valve in such part and for closing the rear end of the latter.

of oppositely rvoluble simultaneously operable rotor operating shafts each extending into a rotor chamber, a pair of oppositely disposed rotors of like form each arranged in a rotor chamber and including a hub fixed to a rotor shaft and a crescent-shaped portion offset with respect to the hub, a pair of uid inlet means each for a chamber, a pair of fluid outlet means each for a chamber, said rotors being so related to said pair of. iiuid intake means whereby one of said uid inlet means is uncovered by the crescent-shaped portion of one rotor at a time whenA the other fluid intake means is covered by the crescentshaped portion of the other. rotor, each of said outlet means provided intermediate the ends with a check valve seat, check valves within said outlet means for correlating with said seats `and each consisting of a head and a stem, adjustable threaded valve tensioning plugs, arranged Within and threadedly engaging with the Wall of said outlet means, sleeves carried by said plugs and engaging about said stems, and springs engaging about said sleeves bearing at one end against said plugs and at their other ends bearing against said headsa 3. In a fluid pump, a rotor housing formed with a pair of rotor chambers, the combination or a pair oi oppositely revoluble simultaneously operable rotor operating shafts each extending into a rotor chamber, a pair of oppositely disposed rotors of like form each arranged in a rotor chamber and including a hub xed to a rotor shaft and,

a crescent-shaped portion oiiset with respect to the hub, an independent fluid inlet for each chamber, an independent Iiuid conducting off means for each chamber formed with a horizontally disposed portion opening at one end into a chamber' and formed adjacent said endwith a check valve seat, said rotors being so related to said pai?" of iluid inlets whereby one of said fluid inlets is uncovered by the crescent-shaped portion of one rotor at a time when the other fluid inlet is covered by the crescent-shaped portion oi the other rotor, each of conducting-off means having a discharge end opening' at the periphery of the housing below said horizontal portion thereof, check valves Within said horizontal portion and correlating with said seats, each valve including a head and a stern, adjustable valve tensioning plugs threadedly engaging with the walls of said conducting off means for closing the other ends of said horizontal portions, sleeves carried by said plugs and engaging about said stems, and coiled springs about said sleeves bearing at one end against said plugs and at their outer end against said heads.

LEROY Al. THOMSON. 

